Step 3: Setting up the Environment
The App Engine SDK has it's own version of Go so we need to setup the GOPATH and GOROOT variables and while where are at it, lets add the App Engine to the PATH environment variable as well.

There are several ways this could be done, but the easiest is to create a simple batch file.

Save the batch commands shown below to the c:\go_appengine\zae.cmd file and create a short cut to that file on the desktop.

@echo off
rem Setup the Go App Engine environment
set PATH=c:\go_appengine\;%PATH%
set GOROOT=c:\go_appengine\goroot
set GOPATH=c:\go_appengine\gopath
rem Run a new instance of Zeus using those settings
start "" "C:\Program Files (x86)\Zeus\zeus.exe" -s

This batch file sets up the environment variables for the App Engine and starts a new instance of Zeus.

Step 4: Tell Gocode About the App Engine
The App Engine used the suffix option when it created its packages and that stops gocode from finding those packages.

For example depending on the CPU type, the App Engine will install package folders similar to these:

lib-pathA string option. Allows you to add search paths for packages. By default, gocode only searches $GOPATH/pkg/$GOOS_$GOARCH and $GOROOT/pkg/$GOOS_$GOARCH in terms of previously existed environment variables. Also you can specify multiple paths using ':' (colon) as a separator (on Windows use semicolon ';'). The paths specified by lib-path are prepended to the default ones.